Josef Alexander Martínez Mencia (born 19 May 1993) is a Venezuelan professional footballer who plays as a striker for Major League Soccer club San Jose Earthquakes and the Venezuela national team.

Martínez made his debut for Caracas on 21 August 2010 against Estudiantes de Mérida, entering as a substitute in the 70th minute, won 1–0.

[2] On 3 January 2012, Caracas announced Martínez had been sold to Young Boys of the Swiss Super League for a period of four years along with fellow right-back Alexander Gonzalez.

After a string of good performances, Martínez was called up to the Venezuela national team, as well as awarded his first start for Young Boys on 21 October 2012, in which he scored his first goal for the Swiss club with a volley in the 50th minute against Grasshoppers.

After scoring eight goals in 18 games with the team from Bernese Oberland, he was momentarily the top scorer in the Swiss Super League and recalled by Young Boys.

[11] On 2 February 2017, Martínez was loaned with a buying option to Major League Soccer expansion team Atlanta United.

Upon his return from the second injury, he scored hat tricks in two consecutive games against the New England Revolution and Orlando City, and was named the MLS Player of the Month for September 2017.

[19] Atlanta United finished in a tie for third in the Eastern Conference, but were eliminated in the first round of the MLS Cup Playoffs by Columbus Crew.

He was voted the MLS Player of the Month for July after scoring ten goals and adding one assist to lead the Five Stripes to a 3–1–1 record.

[23][24] On 24 August 2018, he scored his 28th goal of the season, a game winner in Orlando City, to break the league single-season record of 27, held by Roy Lassiter, Chris Wondolowski, and Bradley Wright-Phillips.

After failing to capitalize on numerous opportunities, Martínez utilized his quick footwork to cut back against the defender and then chip Joe Bendik to set the record in just his 26th match.

[26] He earned the award having scored in nine straight matches, tying his own MLS record set the previous season, which was also shared with Diego Valeri.

[30] Martínez made his first appearance since early last season on 6 April 2021 in the CONCACAF Champions League against Alajuelense, coming on as a 67th minute substitute in the 1–0 away victory.

[32] In July 2021, after returning from Copa América, it was revealed by coach Gabriel Heinze that Martínez was training away from the team, with no specific reason given.

Martinez will be a very important attacking piece for the team[43] Martínez made his international debut on 7 August 2011 against El Salvador as a substitute in the 76th minute.